Ethics of screening for asymptomatic herpes virus type 2 infection

Introduction

Infection with herpes simplex virus type 2 (HSV-2) is a common sexually transmitted disease. It is mostly asymptomatic, and currently no cure exists.1 The prevalence by age differs between populations and geographical areas.2 Serology tests are commercially available with acceptable sensitivity and specificity and are a valuable aid to diagnosis. However, many questions remain over their use for screening. We use an ethical model to consider the potential biotechnical, medical, epidemiological, and psychosocial advantages and disadvantages of screening at the individual and public health levels.

Transmission

Most people seem to be infected with HSV-2 through a partner who is unaware of having the infection. Virus is shed intermittently from the genital tract of infected asymptomatic people and also between attacks in people with typical mucocutaneous symptoms.3 Patients with unrecognised infections could thus be an important source of sexual transmission.

A serious consequence of genital HSV infection is neonatal herpes, which results from transmission from mother to infant. The risk of perinatal transmission is less than 1% in women with longstanding infection but substantially higher if the maternal infection is acquired during late pregnancy.4 Untreated herpes infection has among the highest mortality of any infection in the neonatal period, and neurological sequelae are common among the survivors.

Identification of infected people

The only practical way to identify people with asymptomatic HSV-2 infection is by serological tests. Discussion is ongoing about how far to extend testing for HSV and for which groups, mostly with arguments from a biomedical perspective.^w2-w12 Routine screening of pregnant women has been advocated, especially in the United States,^w4 but its cost …